1. Field of the Present Invention
The present invention relates to a helical scan type tape drive apparatus adapted so that tape is drawn out of a cartridge accommodating the tape serving as a recording medium, the drawn tape is caused to run in such a way as to be wound onto a tape takeup reel provided in a drive apparatus body, and the tape drawn out of the cartridge is wound around a rotary head drum so that signals are recorded thereon and reproduced therefrom. More particularly, the present invention relates to a mechanism for detecting dew condensation on the rotary head drum.
2. Description of the Related Art
There has been widely practiced a recording/reproducing apparatus of the helical scan type that records and reproduces signals by drawing tape, which serves as a recording medium, out of a cartridge in which the tape is accommodated and by winding this tape around a rotary head drum.
In recent years, for recoding/reproducing apparatuses of such kind, there has been proposed a tape drive apparatus using what is called a single reel type cartridge (see, for example, Japanese Patent Application Laid-Open No. 2002-237117).
In other words, the single reel type cartridge used in this tape drive apparatus is adapted to accommodate only one tape supply reel, around which a tape serving as a recording medium is wound. At the drive apparatus body, tape is drawn out of the tape supply reel when this cartridge is inserted therein. This tape is carried in such a way as to be wound by a tape takeup reel provided in the drive apparatus body. Thus, the tape drive apparatus operates such that tape running is performed in this manner.
An outline of a conventional tape drive apparatus of such kind is described hereinbelow with reference to FIG. 14 to FIG. 16.
FIG. 14 shows an entire configuration of the tape drive apparatus. In an apparatus body 1 of this tape drive apparatus, a section, in which a cartridge 4 is mounted, and a tape takeup reel 6 are disposed on a base chassis 2 so that a rotary head drum 3 is interposed therebetween.
A tape supply reel 5 is rotatably accommodated in a cartridge 4, around which tape serving as a recording medium (or magnetic tape) is wound. A carrying mechanism 7 for drawing tape from the tape supply reel 5 provided in the cartridge 4 and for carrying the tape to the tape takeup reel 6 is placed between the section in which this cartridge 4 is mounted and the tape takeup reel 6.
This carrying mechanism 7 is constructed on a subplate 8 fixed onto an upper section of the apparatus body 1. That is, on this subplate 8, a guide shaft 9 is provided in such a way as to extend over the section, in which this cartridge 4 is mounted and the tape takeup reel 6. A chucking mechanism 10 is provided on this guide shaft 9 in such a manner as to be able to move therealong. This chucking mechanism 10 is connected to a feed belt 12 driven by a motor 11. That is, this carrying mechanism 7 has a structure in which the feed belt 12 is driven by the motor 11, thereby to move the chucking mechanism 10 along the guide shaft 9.
A chucking member to be engaged with a leader block 13 (see FIG. 15) attached to an end of tape T is mounted on this chucking mechanism 10. When the cartridge 4 is mounted on the apparatus body 1, this chucking member engages with and chucks the leader block 13. Then, the motor 11 drives the chucking mechanism 10 from this state, so that the chucking mechanism 10 is moved from the side of the cartridge 4 toward the tape takeup reel 6. Thus, the leader block 13 is carried along a guide groove 14 formed in the subplate 8. Consequently, the tape T is drawn out of the cartridge 4 and carried to a position where the tape T is wound up by the tape takeup reel 6.
Thus, the leader block 13 carried by the carrying mechanism 7 is fixed to the tape takeup reel 6 in a state in which the leader block 13 is fitted into a central section of the tape takeup reel 6 from a lead-in groove 15, as shown in FIGS. 15 and 16. Thereafter, a tape winding mechanism operates, so that the tape T is wound around the rotary head drum 3 by tape winding members 16 and 17.
These tape winding members 16 and 17 have guide rollers 20 and 21 and inclined guide posts 22 and 23 on movement plates 18 and 19, respectively. The movement plates 18 and 19 are adapted to be moved to positions shown in FIG. 15 and FIG. 16, respectively. Thus, the guide rollers 20 and 21 and the inclined guide posts 22 and 23 draw the tape T, so that the tape T is wound around the rotary head drum 3 at an angle (about 200 degrees) set to be within a predetermined range. Incidentally, the movement plates 18 and 19 of these tape winding members 16 and 17 are adapted to be moved along guide grooves 24 and 25 provided in both sides of the rotary head drum 3, respectively, as shown in FIG. 14.
Reference numerals 26, 27, 28, and 29 designate guide rollers. Along with winding of the tape T around the rotary head drum 3, these guide rollers are moved from a position shown in FIG. 15 to a position shown in FIG. 16. Thus, a predetermined tape path is formed.
Reference numeral 30 denotes a tension regulator. This tension regulator 30 has a roller 33 provided at a tip end of an arm 32 that is turned around a shaft 31 serving as a fulcrum. During a state in which the tape T is wound around the rotary head drum 3 as shown in FIG. 16, the roller 33 of this tension regulator 30 is brought into rolling contact with the tape T by the force of a spring (not shown). Thus, predetermined tension is given to the tape T.
Thus, the tape takeup reel 6 is rotation-driven thereby to wind up the tape T, which has been wound around the rotary head drum 3, onto the tape takeup reel 6, thus the tape T runs and at the same time the rotary head drum 3 is rotation-driven. Thus, a signal is recorded onto or reproduced from the tape T.